All transactions within the IRA account are generally tax free as long as the money remains in the account. So yes, you can trade stocks, invest temporarily in money markets or mutual funds, freely with no tax impact. The taxes are due only when the money comes out of the account (in the case of a traditonal IRA or 401K, but only as penalty distributions in the case of a Roth).

The ability to trade securities freely is the main advantage of an IRA account compared to LTBH.